docs: def _remove_node(self, node_name):
          """Remove the given node from the continuum/ring.
  
          :param node_name: the node name.
          """
          try:
              self._nodes.pop(node_name)
          except Exception:
              raise KeyError('node \'{}\' not found, available nodes: {}'.format(
                  node_name, self._nodes.keys()))
          else:
              self._create_ring(self._nodes)